How to wire cheap speedo

[AussiXS]

A title I have been searching for, and other, with no answers to find . So I thought I would post it so this can be a place to be the definitive guide to installing an aftermarket speedo with current set up.

My prediciment:
I have a Jap import 78, its got stock harness. I am swapping out the current speedo, rev and lighting cluster. The new one has a backlight, neutral, blinker light, high beam and no rev counter. The issue is that I have to cut down from like 18 wires down to 7. How do I get the right wires in the right place? The neutral light, for instance, is Green on my speedo but requires a brown and aqua on the stock. How do I put 2 wires into one without it blowing up? There are 2 black wires, one for ground and another for the power for all warning lights of the speedo. What goes where?

I am quite new to this but I understand it needs to be a loop but I cant just attached 5 wires to the 1 power cable can I? I just dont want to blow shit up.

Ps, any ideas how to plug the rev cable hole in engine?

 

[AussiXS]

Images

 

[mrtwowheel]

The other lights will be easy once you get them figured out..........but........the neutral light is the tricky one since all of the lights in that gauge probably use the same ground wire and the YAMAHA has the cursed switched ground for the neutral light, if it were a Honda this would be no problem. I have my similar gauge figured out but maybe someone else could do a better job explaining this. Will check your thread again tomorrow.

EDIT - NIX on that neutral light rant, you do have a separate ground for the gauges' neutral light, your gauge is more "universal" than mine.

Scott

 

[TwoManyXS1Bs]

Is the lighting on your new instrument provided by LEDs?
If so, gotta watch polarities...

 

[mrtwowheel]

After extensive research, years of education and accidental experience

gauge black #1 to harness black

gauge blue to harness yellow

gauge yellow to harness green

gauge yellow to harness brown

gauge red to harness dark blue

gauge green to harness brown

gauge black #2 to harness light blue

Only connect the gauge wires to the corresponding colors above in the original wires going to the original gauges, other wires of the same color in other parts of the harness may not work.

You do have an obligation to report back concerning your results. This should work

Scott

 

[AussiXS]

Yes, they do have LEDS, this is the speedo I have, the wiring is in the above post.

What do you mean by polarity?

Are LEDs directional for their postive and negative, meaning one side has to have positive and the other has to be negative? Anyone have a wiring diagram or know how and where to connect this? I plan on doing a video once I figure this out, its the way I learn best

 

[AussiXS]

After extensive research, years of education and accidental experience

gauge black #1 to harness black

gauge blue to harness yellow

gauge yellow to harness green

gauge yellow to harness brown

gauge red to harness blue

gauge green to harness brown

gauge black #2 to harness light blue

Only connect the gauge wires to the corresponding colors above in the original wires going to the original gauges, other wires of the same color in other parts of the harness may not work.

You do have an obligation to report back concerning your results. This should work

Scott

You posted as I posted!

When you say "gauge black #1 to harness black", is that referring to a frame negative?

 

[mrtwowheel]

You posted as I posted!

When you say "gauge black #1 to harness black", is that referring to a frame negative?

You have 2 black wires coming from the gauge. Are they marked 1 and 2? One black wire goes to ground, a black wire in your harness. The other black wire from the gauge, #2, goes to the light blue wire for the neutral light ground.

 

[AussiXS]

Thanks for the tips, I have a video to show my progress. It's my birthday and my girlfriend said I could "do anything", so I decided to work on my bike. If you don't feel like watching my 5 min monologue then I'll write the jist of it. I did as you said and it all works, yay! The only thing is, is that the high beam (blue wire from speedo to yellow harness) stays on, then when I take it out of neutral, the high beam goes off. What could that be? I think it may be the continuity from the switch to the bars, as I took that off. I was going to set it all up but I then thought my girlfriend had some other meaning to her lovely offering. Turns out I was too late and she is sleeping, hence me writing all this. I wish I wasn't . Anyway, anyone know what's happening?

*Click link for video* https://drive.google.com/open?id=0B3tSQlhhBRz9ZWRidFg1bnJNM2M

 

[mrtwowheel]

I'm not sure what is going on with the high beam light, someone may figure this out, or I may have more time to go over the diagram and video later tonight.

Scott

 

[XSLeo]

The stock neutral light, power goes to the bulb on a brown wire, the Sky blue wire goes to the neutral switch on the top of tranny. When in neutral the switch grounds the sky blue wire.
On the tach cable, just unscrew the cable from the adapter in the case, You can buy covers that go on the adapter or just leave it.
I would not remove the tach drive from the case. This way I can hook a tach back up for tune ups. But then I would put a tach back on. I like a tach.
All diodes are polarity sensitive, they are a one way valve, you have to hook them up right or you get no light. Positive to positive, ground to ground.
On the rest of your lighting you need to determine which wires do what. I would use a batter and use jumper wires to hook the black wires to ground, then touch each the wires to the positive. Make notes as you do this so you will know which wire light up which lights.
Did the speedo come with instructions that list which color wires do what?
Here's a diagram of the tach drive. The cable screws on to #4 in the diagram. #3 is the seal around shaft 37. If you want to remove the shaft you need to pull the right side engine cover, #8 is a spacer that prevent the shaft from chewing into the softer alloy of the case.
If you just pull out screw #5 you can pull out parts #1,2,and 7 but the spacer stays in the engine. The spacer is just a thick washer. If you don't get it out it will float around in your engine till it finds a place to land. Which will be in a place that can do severe damage.
Leo

 

[AussiXS]

Hey,

I can't seem to find the image you're talking about the tach drive. Where would I be able to get a cover from? You're right, I'll keep it all there so I can turn it. I'll probably get sick of not seeing the revs and put it back on.

As for a wiring diagram there is one of the previous posts above, it's the 7 wires.

The issue is that the high beam light stays on there whole time or when ever I take it out of neutral. It's weird.

 

[TwoManyXS1Bs]

...The only thing is, is that the high beam (blue wire from speedo to yellow harness) stays on, then when I take it out of neutral, the high beam goes off. What could that be?

...The issue is that the high beam light stays on there whole time or when ever I take it out of neutral. It's weird.

What does the neutral light do during all this?
Are both neutral and hibeam lights doing the same thing, on or off together?

 

[mrtwowheel]

At the start of this I knew that there may be a chance that those two grounds may have to be swapped. I don't think that is what is wrong. Hard to figure out from here without being there.

Scott